JP6347696B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge having an electrophotographic photosensitive member, and an electrophotographic apparatus.

  At present, electrophotographic photoreceptors containing organic photoconductive substances are mainly used as electrophotographic photoreceptors used in process cartridges and electrophotographic apparatuses. An electrophotographic photoreceptor generally has a support and a photosensitive layer formed on the support. An intermediate layer is provided between the support and the photosensitive layer for the purpose of suppressing charge injection from the support side to the photosensitive layer (charge generation layer) side and suppressing the occurrence of image defects such as fogging. Yes. It is also known to provide a conductive layer containing metal oxide particles for the purpose of covering defects on the surface of the support.

  In recent years, charge generation materials having higher sensitivity have been used. However, as the charge generation material becomes more sensitive, the amount of generated charge increases, so that when the same image is output in a short amount of time, the exposed portion of the charge stays in the photosensitive layer. There is a problem that it is easy to do. As a technique for suppressing such charge retention in the photosensitive layer, a technique in which an electron transport material is contained in the intermediate layer, and the intermediate layer is a layer having an electron transport ability (hereinafter also referred to as “electron transport layer”). It has been known.

  Patent Document 1 includes an electron transport layer containing an aromatic tetracarbonylbisimide skeleton, a condensation polymer (electron transport material) having a crosslinking site, and a polymer with a crosslinking agent, and a conductive layer containing tin oxide particles. An electrophotographic photosensitive member is described. Patent Document 2 describes an electrophotographic photoreceptor having a layer containing an electron-accepting substance, and a conductive layer containing zinc acceptor particles surface-treated with the electron-accepting substance and a silane coupling agent. .

  Patent Documents 3 and 4 describe an electrophotographic photoreceptor having an electron transport layer on a conductive layer containing tin oxide-coated titanium oxide particles.

Special table 2009-505156 JP 2008-65173 A JP 2007-148294 A JP 2008-250082 A

  In recent years, the demand for the quality of electrophotographic images has been increasing, and the opportunity to output a large amount of the same image in a short time has increased.

  As a result of the study by the present inventors, it has been found that an image defect called a pattern memory is likely to occur in that case. The pattern memory is a continuous output of a large amount of the image 301 including the vertical line 306 of FIG. 3 and then outputting the solid black image 302. The output solid black image is a repetition of the vertical line 306 of the image 301 of FIG. This is a phenomenon that the image 304 includes a vertical line 307 caused by a history. When the halftone image 303 is output after a large amount of the image 301 in FIG. 3 is continuously output, the vertical line caused by the repetition history of the vertical line 306 in the image 301 in FIG. 3 is output as in the case of the solid black image. This is a phenomenon that becomes an image 305 containing 308.

  In the electrophotographic photosensitive member having the conductive layer and the electron transport layer or the electron-accepting substance-containing layer described in Patent Documents 1 and 2, charges easily accumulate between the conductive layer and the electron transport layer, and the above pattern It was found that memory might occur.

  Therefore, in order to suppress charge retention between the conductive layer and the electron transport layer, it is conceivable to increase the content of metal oxide particles in the conductive layer to lower the electrical resistance. However, it has been found that when the electrical resistance of the conductive layer is lowered in this way, the adhesion of the electron transport layer is not sufficient, and leakage is likely to occur in the electrophotographic photosensitive member when a high voltage is applied. . Leakage is a phenomenon in which dielectric breakdown occurs in a local portion of the electrophotographic photosensitive member, and an excessive current flows through that portion. When leakage occurs, the electrophotographic photosensitive member cannot be sufficiently charged, and image defects such as black spots and horizontal black stripes may occur.

  An object of the present invention is to provide an electrophotographic photosensitive member in which pattern memory is suppressed and leakage is hardly generated, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

The present invention is an electrophotographic photosensitive member having a laminate, a charge generation layer formed on the laminate, and a hole transport layer formed on the charge generation layer,
The laminate has a conductive support, a first intermediate layer formed on the conductive support, and a second intermediate layer formed on the first intermediate layer,
The first intermediate layer contains a binder resin and metal oxide particles surface-treated with an organic compound,
The second intermediate layer contains a cured product having electron transport properties,
The laminate is represented by the following formula (1)
R_nV / R_0V ≦ 0.80 Formula (1)
(Where
For R_nV, a circular gold electrode having a thickness of 300 nm and a diameter of 12 mm is provided on the surface of the second intermediate layer by vapor deposition, and a DC electric field of −0.3 V / μm is applied from the conductive support to the gold electrode. It represents the impedance measured by applying an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz between the conductive support and the gold electrode while applying.

R_0V provides a circular gold electrode having a film thickness of 300 nm and a diameter of 12 mm on the surface of the second intermediate layer by vapor deposition, and applying a DC electric field of 0 V from the conductive support to the gold electrode, It represents impedance measured by applying an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz between the conductive support and the gold electrode. )
An electrophotographic photoreceptor characterized by satisfying the above.

  The present invention also integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. The present invention relates to a process cartridge.

  The present invention also relates to an electrophotographic apparatus comprising the electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member in which pattern memory is suppressed and leakage is hardly generated, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

1 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a process cartridge including an electrophotographic photosensitive member. It is a figure which shows an example of schematic structure of the determination apparatus for enforcing the determination method of this invention. It is a figure explaining a pattern memory. FIG. 4A is a diagram (top view) for explaining a method for measuring the volume resistivity of the first intermediate layer. FIG. 4B is a cross-sectional view of FIG. It is a figure explaining a 1 dot Keima pattern image. It is a figure which shows an example of the layer structure of an electrophotographic photoreceptor. It is a figure which shows the representative example of R_nV and R_0V at the time of implementing the determination method of this invention.

  The electrophotographic photoreceptor of the present invention has a laminate, a charge generation layer formed on the laminate, and a hole transport layer formed on the charge generation layer. The laminate has a conductive support, a first intermediate layer formed on the conductive support, and a second intermediate layer formed above.

In the electrophotographic photoreceptor of the present invention, the laminate is represented by the following formula (1).
R_nV / R_0V ≦ 0.80 Formula (1)
(In the formula, R_nV and R_0V represent impedances measured as follows.)
It is characterized by satisfying.

First, a circular gold electrode having a thickness of 300 nm and a diameter of 12 mm is provided by vapor deposition on the surface of the second intermediate layer of the laminate. Next, while applying a DC electric field of −0.3 V / μm from the conductive support to the gold electrode, 3.0 × 10 ⁻³ V / μm and 0.1 Hz between the conductive support and the gold electrode. Impedance is measured by applying an alternating electric field. The −0.3 V / μm DC electric field means that a −0.3 V DC electric field is applied to the unit thickness (μm) of the total thickness of the first intermediate layer and the second intermediate layer. . The AC electric field of 3.0 × 10 ⁻³ V / μm is 3.0 × 10 ⁻³ V with respect to the unit thickness (μm) of the total thickness of the first intermediate layer and the second intermediate layer. An AC electric field is applied. The peak-to-peak value of the sine wave of the AC electric field of 3.0 × 10 ⁻³ V / μm is 6.0 × 10 ⁻³ V / μm.

R_0V represents the impedance measured as follows. First, the above-mentioned gold electrode is provided on the surface of the second intermediate layer of the laminate by an evaporation method. Next, while applying a DC electric field of 0 V from the conductive support to the gold electrode, an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz is applied between the conductive support and the gold electrode. Apply and measure impedance.

  First, a determination method (hereinafter referred to as “determination method of the present invention”) for determining whether or not the electrophotographic photosensitive member satisfies the relationship of the above formula (1) will be described. The temperature and humidity conditions when performing the determination method of the present invention may be in an environment where an electrophotographic apparatus having an electrophotographic photosensitive member is used. Preferably, it is in a normal temperature and normal humidity environment (temperature 23 ° C. ± 3 ° C., humidity 50% ± 5% RH).

  This measuring method is performed using the above-mentioned laminate. In that case, the hole transport layer and the charge generation layer are peeled from the electrophotographic photosensitive member having the laminate, the charge generation layer formed on the laminate, and the hole transport layer formed on the charge generation layer. Thus, it is preferable to use a laminate and use it as a measurement target. There are two methods for peeling the hole transport layer and the charge generation layer. In the first method, the hole transport layer and the charge generation layer are dissolved, and the electrophotographic photosensitive member is immersed in the second intermediate layer using a hardly soluble solvent, and the hole transport layer and the charge generation layer are peeled off. Is the method. The second method is a method of polishing the hole transport layer and the charge generation layer.

  The solvent that dissolves the hole transport layer and the charge generation layer and is hardly soluble in the second intermediate layer is preferably a solvent used for the hole transport layer coating solution or the charge generation layer coating solution. The type of the solvent will be described later. It is possible to obtain a laminate by immersing the electrophotographic photoreceptor in this solvent, dissolving the hole transport layer and the charge generation layer in the solvent, and then drying. The fact that the hole transport layer and the charge generation layer are peeled off means that, for example, the resin component of the hole transport layer and the charge generation layer is not observed by the ATR method (total reflection method) in the FT-IR measurement method. Can be confirmed.

  Further, as a method for polishing the hole transport layer and the charge generation layer, for example, a wrapping tape (C2000: manufactured by Fuji Photo Film Co., Ltd.) is used, and the pressing pressure is controlled to 0.005 N / m 2 or more and 15 N / m 2 or less. And a polishing method. At that time, measure the film thickness sequentially so that the charge generation layer is not excessively polished and not polished to the second intermediate layer, and the hole transport layer and the charge generation layer are all removed while observing the surface of the electrophotographic photoreceptor. It is preferable. In addition, when the charge generation layer is polished and the second intermediate layer is further polished to a thickness of 0.10 μm or more, the above determination method is used even if the second intermediate layer is not polished. It has been confirmed that almost the same value can be obtained. Therefore, if the second intermediate layer has a film thickness of 0.10 μm or more, not only the hole transport layer and the charge generation layer but also the second intermediate layer, the above-described determination method can be used. is there.

  In FIG. 2, an example of schematic structure of the determination apparatus for enforcing the determination method of this invention is shown. In FIG. 2, a laminate 101 cut out at 2 cm (circumferential direction) × 4 cm (long axis direction) is set as a measurement target. A circular gold electrode 102 having a diameter of 12 mm and a film thickness of 300 nm is provided on the surface of the second intermediate layer of the laminate by vapor deposition. As a method for depositing the gold electrode, Quick Auto Coater (SC-707AT) manufactured by SANYU DENSHI can be used. With a configuration in which a gold target is disposed on the surface of the second intermediate layer, vapor deposition is performed until the film thickness reaches 300 nm so as to maintain a discharge current of 20 mA, thereby producing a gold electrode. It shows that the conductive wire 105 is connected to the gold electrode on the second intermediate layer and the conductive support, and the impedance measuring machine 103 is connected to the conductive wire 105. As the impedance measuring device, for example, a measurement module combining SI-1287-electrochemical-interface, SI-1260-impedance-gain-phase-analyzer, and 1296-dielectric-interface manufactured by Toyo Technica is used.

In the present invention, the impedance is measured by blocking the entire apparatus of FIG. 2 from room light. In the formula, R_0V sets a value of 0V to “DC Level” and applies a DC electric field of 0V from the conductive support to the gold electrode. Furthermore, the value is set so as to be 3.0 × 10 ⁻³ V / μm from the thickness of the total thickness of the first intermediate layer and the second intermediate layer on “AC Level”, and the conductive support An AC electric field of 3.0 × 10 ⁻³ V / μm is applied between the electrode and the gold electrode. Next, the impedance is measured by sweeping the frequency of the alternating electric field from 1 MHz, which is a high frequency, to 0.1 Hz, which is a low frequency, and an impedance (R_0V) at 0.1 Hz is obtained. That is, R_0V applies a DC electric field of 0 V from the conductive support to the gold electrode, and an AC electric field of 3.0 × 10 ⁻³ V / μm, 0.1 Hz is applied between the conductive support and the gold electrode. It represents the impedance measured when applied.

Next, R_nV is set to a value of −0.3 V / μm from the thickness of the total thickness of the first intermediate layer and the second intermediate layer in “DC Level”, and from the conductive support. A DC electric field of −0.3 V / μm is applied to the gold electrode. Furthermore, from the thickness of the total thickness of the first intermediate layer and the second intermediate layer on “AC Level”, 3.0 × 10 ⁻³ V / μm so as to be 3.0 × 10 ⁻³ V / μm. The AC electric field of 3.0 × 10 ⁻³ V / μm is applied between the conductive support and the gold electrode. Next, the impedance is measured by sweeping the frequency of the alternating electric field from 1 MHz, which is a high frequency, to 0.1 Hz, which is a low frequency, and the impedance (R_nV) at 0.1 Hz is obtained. That is, R_nV is 3.0 × 10 ⁻³ V / μm between the conductive support and the gold electrode while applying a direct electric field of −0.3 V / μm from the conductive support to the gold electrode. Represents the impedance measured by applying an alternating electric field of 1 Hz.

  FIG. 7 shows representative examples of R_nV and R_0V. The vertical axis and the other axis are logarithmic scales. In FIG. 7, the frequency dependence of the impedance (R_nV and R_0V) measured by the above-mentioned method is shown. In particular, on the low frequency side, the change in impedance is large due to the difference in the magnitude of the applied DC electric field. That is, it represents that the ratio of R_nV / R_0V is 0.80 or less at 0.1 Hz.

  In the present invention, in order to suppress the pattern memory, the ratio of R_nV / R_0V is 0.80 or less. The present inventors presume the reason why the pattern memory is suppressed when the laminate of the present invention satisfies the above formula (1) as follows.

  The pattern memory is considered to be suppressed by forming a good conductive path in a wide range between the first intermediate layer and the second intermediate layer. That is, it is considered that the charge (electrons) staying in the second intermediate layer is uniformly injected into the first intermediate layer, thereby suppressing the pattern memory. The reason for this is considered to be that the local charge accumulation or accumulation in the first intermediate layer is suppressed, and the flow of charges is smooth.

  In the electrophotographic photoreceptor of the present invention, in the portion exposed to the exposure light (image exposure light), among the charges (holes and electrons) generated in the charge generation layer, the holes are injected into the hole transport layer, and the electrons Is injected into the second intermediate layer and the first intermediate layer and moves to the conductive support. However, if the electrons generated in the charge generation layer by photoexcitation cannot move through the second intermediate layer and the first intermediate layer before the next charging, the electrons stay at the interface between the first intermediate layer and the second intermediate layer, Electron movement still occurs at the next charging. These phenomena are likely to occur when the electrophotographic photosensitive member is repeatedly used, and the electrons staying at the interface between the first intermediate layer and the second intermediate layer are likely to increase. The increase of the staying electrons is considered to be caused by the trapping of electric charges in the conduction level barrier or the trap level between the first intermediate layer and the second intermediate layer. It is considered that the slow-moving electrons generated by the electrons staying at the interface between the first intermediate layer and the second intermediate layer cause the pattern memory described above.

  In order to suppress the retention of electrons, the first intermediate layer contains a metal oxide particle surface-treated with an organic compound and a binder resin, and the second intermediate layer has a cured product (electron transport curing). Product). With this configuration, it is considered that the retention of electrons is reduced by the cured product having the conductivity of the metal oxide particles of the first intermediate layer and the electron transport property of the second intermediate layer. However, in the electrophotographic photosensitive member having the first intermediate layer and the second intermediate layer, the pattern memory may not be sufficiently suppressed, and it is further necessary to satisfy the above formula (1).

  When the laminate satisfies the above formula (1), it is considered that the transfer of electrons is promoted at the interface between the second intermediate layer and the first intermediate layer. In the present invention, when impedance is measured using an electrophotographic photosensitive member having a charge generation layer and a hole transport layer, it becomes difficult to correctly capture the movement of electrons at the interface between the second intermediate layer and the first intermediate layer. It is necessary to perform the evaluation method of the present invention using the laminate. However, since the laminate does not have a charge generation layer, electrons generated in the charge generation layer by photoexcitation are not generated. Therefore, as described in the evaluation method of the present invention, when a DC electric field of −0.3 V / μm is applied to the laminate, the electrons generated in the charge generation layer by pseudo photoexcitation are revealed. thinking. In other words, by applying a specific DC electric field between the first intermediate layer and the second intermediate layer, electrons accumulated in the trap level of the second intermediate layer are emitted, and the conduction level of the second intermediate layer is released. It is thought that the conduction level of the first intermediate layer moves from the position.

  In the determination method of the present invention, if a −0.3 V / μm DC electric field is applied and does not change when a 0 V DC electric field is applied, electrons from the second intermediate layer to the first intermediate layer Insufficient injection of electrons tends to retain electrons and increase the number of slow moving electrons. The tendency is considered to be when the value of R_nV / R_0V is greater than 0.80. On the other hand, if the value of impedance is smaller when a DC electric field of −0.3 V / μm is applied than when a DC electric field of 0 V is applied, electrons from the second intermediate layer to the first intermediate layer It is considered that the injection of this is sufficiently performed. As a result, it is considered that the slow movement of electrons in the second intermediate layer is suppressed, and the retention of electrons is reduced.

  The degree of the slow movement of electrons can be determined by paying attention to the impedance at a low frequency. In the evaluation method of the present invention, attention is paid to 0.1 Hz as a low frequency. However, any frequency that is lower than 0.1 Hz can express the impedance of this slow moving electron. It is considered possible. In the present invention, the impedance of electrons that move slowly is observed at an impedance of 0.1 Hz. 0.1 Hz is a period of about 10 seconds, and through repeated use of the electrophotographic photosensitive member, electrons that respond to an electric field with a period of about 10 seconds stay at the interface between the second intermediate layer and the first intermediate layer, It is thought that it represents a state where pattern memory is likely to occur.

  When the above formula (1) is satisfied, a good injection property is exhibited such that an increase in slowly moving electrons is suppressed. Then, it is considered that the retention of electrons is reduced and the pattern memory can be reduced when the electrophotographic photosensitive member is repeatedly used.

Japanese Patent Application Laid-Open No. 2005-189964 describes that the charge mobility of the undercoat layer (second intermediate layer) is 10 ⁻⁷ cm ² / V · sec or more. However, the electrophotographic photosensitive member described in Japanese Patent Application Laid-Open No. 2005-189664 is intended to improve the speed of electron movement more quickly, and does not suppress an increase in electrons that move slowly. Conceivable. Further, in Japanese Patent Application Laid-Open No. 2005-189964, in order to measure the electron mobility of the second intermediate layer, a second intermediate layer is formed on the charge generation layer, which is opposite to the layer configuration used in the electrophotographic photoreceptor. The measurement is performed in the configuration of However, in such a measurement, it cannot be said that the movement of electrons in the second intermediate layer of the electrophotographic photosensitive member can be sufficiently evaluated.

  For example, when an electron transport material is contained in the second intermediate layer to form an electron transport layer, a charge generation layer coating solution and a hole transport layer coating solution are applied to the charge generation layer and the hole transport layer. When the layer is formed, the electron transport material may be eluted. In this case, even when the electron mobility is measured using the second intermediate layer and the charge generation layer as the opposite layers as described above, the electron transport material is eluted, so that the electron transfer of the second intermediate layer is sufficiently performed. It is thought that it has not been evaluated. Therefore, it is thought that it is necessary to determine by the evaluation method of the present invention using the laminate having the layer structure of the present invention.

In the present invention, it is preferable that the value of R_nV / R_0V satisfies the following formula (2) because the pattern memory can be further reduced. Further, the smaller the value of R_nV / R_0V is, the more effect of reducing the pattern memory is obtained.
0.40 ≦ R_nV / R_0V ≦ 0.75 Formula (2)
The electrophotographic photoreceptor of the present invention has a laminate, a charge generation layer formed on the laminate, and a hole transport layer formed on the charge generation layer. The laminate has a conductive support, a first intermediate layer formed on the conductive support, and a second intermediate layer formed on the first intermediate layer.

  FIG. 6 is a diagram showing an example of the layer structure of the electrophotographic photosensitive member. In FIG. 6, the electrophotographic photosensitive member includes a conductive support 701, a first intermediate layer 702, a second intermediate layer 703, a charge generation layer 704, and a hole transport layer 705.

  As a general electrophotographic photoreceptor, an electrophotographic photoreceptor in which a photosensitive layer (a charge generation layer, a hole transport layer) is formed on a cylindrical conductive support is widely used. It is also possible to have a shape such as

[First intermediate layer]
The first intermediate layer contains a binder resin and metal oxide particles surface-treated with an organic compound.

  Examples of the binder resin include phenol resin, polyurethane resin, polyamide resin, polyimide resin, polyamideimide resin, polyvinyl acetal resin, epoxy resin, acrylic resin, melamine resin, and polyester resin. These can be used alone or in combination of two or more. Among these binder resins, from the viewpoints of resistance to a solvent in a coating solution used for forming other layers, adhesion to a conductive support, dispersibility / dispersion stability of metal oxide particles, A curable resin is preferred. More preferably, it is a thermosetting resin. Examples of the thermosetting resin include a thermosetting phenol resin and a thermosetting polyurethane resin. When a curable resin is used as the binder resin for the first intermediate layer, the first intermediate layer coating solution contains a monomer and / or an oligomer of the curable resin.

  It does not specifically limit as an organic compound used in order to surface-treat a metal oxide particle, It selects from what is an organic compound among well-known surface treatment agents. Examples include silane coupling agents, titanate coupling agents, aluminum coupling agents, and surfactants. Preferably, an organic compound having an alkoxysilyl group, an amino group, an epoxy group, a carboxyl group, a hydroxy group, or a thiol group is used. From the viewpoint of electrophotographic characteristics, a silane coupling agent is more preferable.

  The molecular weight of the organic compound is preferably in the range of 100 to 1000. Within this range, it is possible to further improve the effect of suppressing leakage and the reduction of residual charge accumulation.

  Examples of the compound having an alkoxysilyl group include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyl. Examples include dimethoxysilane and N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane.

  Examples of the compound having an amino group include hexylamine, n-octylamine, n-decylamine, 1-aminododecane, 1-tetradecylamine, and 1-hexadecylamine.

  Examples of the compound having an epoxy group include 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxynonane, 1,2-epoxydecane, and 1,2-epoxy. Examples include undecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, and 1,2-epoxypentadecane.

  Examples of the compound having a carboxyl group include heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid and hexadecanoic acid.

  Examples of the compound having a hydroxy group include 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1- Examples include pentadecanol.

  Examples of the compound having a thiol group include 1-hexanethiol, 1-heptanethiol, 1-octanethiol, 1-nonanethiol, 1-decanethiol, 1-undecanethiol, 1-dodecanethiol, 1-tridecanethiol. , 1-tetradecanethiol, 1-pentadecanethiol.

  By subjecting the metal oxide particles to a surface treatment with the organic compound as described above, it is possible to stably maintain the dispersion state of the metal oxide particles in the first intermediate layer, and to uniformly distribute the first intermediate layer. It is considered possible to form a conductive path. Thereby, it is considered that the current is suppressed from being concentrated on the local conductive path, and the leakage is suppressed.

  The surface treatment method for surface-treating the metal oxide particles includes known methods, and a dry method or a wet method is used.

  When surface treatment is performed on metal oxide particles by a dry method, an organic compound dissolved in an organic solvent is added while stirring the metal oxide particles with a mixer having a large shearing force, and dry air or nitrogen is added. Surface treatment is performed by spraying with gas. The addition or spraying is preferably performed at a temperature not higher than the boiling point of the organic solvent. After addition or spraying, baking may be further performed at a temperature of 100 ° C. or higher. The baking temperature and time are carried out in an arbitrary range.

  In addition, as a wet method, metal oxide particles are stirred in a solvent, dispersed using an ultrasonic wave, a sand mill, an attritor, or a ball mill, added with an organic compound, stirred or dispersed, and then the organic solvent is removed. Perform surface treatment. As a method of removing the organic solvent, there is a method of distilling off by filtration or distillation. After removing the organic solvent, baking may be performed at a temperature of 100 ° C. or higher. The baking is not particularly limited as long as it is a temperature and time for obtaining electrophotographic characteristics.

  The addition amount of the organic compound used when surface-treating the metal oxide particles in the first intermediate layer is preferably 0.5% by mass or more and 20% by mass or less with respect to the metal oxide particles.

  Examples of the metal oxide particles include zinc oxide, lead white, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, bismuth oxide, tin-doped indium oxide and antimony. And tin oxide particles doped with tantalum. Among these, particles of zinc oxide, tin oxide, and titanium oxide are preferable. In particular, titanium oxide particles are hardly absorbed with respect to visible light and near-infrared light, and are white, which is preferable from the viewpoint of increasing sensitivity. Two or more kinds of metal oxide particles may be selected from the above metal oxide particles and used in combination.

  Examples of the crystal type of titanium oxide include a rutile type, anatase type, brookite type, and amorphous type, and any crystal type may be used. Moreover, you may also use the titanium oxide particle of a needle-like crystal and a granular crystal. More preferably, the particles are rutile type titanium oxide crystals.

  The average primary particle size based on the number of metal oxide particles is preferably 0.05 to 1 μm, and more preferably 0.1 to 0.5 μm, from the viewpoint of suppressing leakage and suppressing pattern memory. .

  The first intermediate layer is formed by applying a coating solution for the first intermediate layer containing a metal oxide particle surface-treated with a solvent, a binder resin, and an organic compound on a conductive support, It can be formed by drying and / or curing the resulting coating.

  The first intermediate layer coating liquid can be prepared by dispersing metal oxide particles surface-treated with an organic compound in a solvent together with a binder resin. Examples of the dispersion method include a method using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

  Examples of the solvent used in the first intermediate layer coating solution include alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, tetrahydrofuran, dioxane, ethers such as ethylene glycol monomethyl ether and propylene glycol monomethyl ether, Examples thereof include esters such as methyl acetate and ethyl acetate, and aromatic hydrocarbons such as toluene and xylene.

  Further, in order to suppress the generation of interference fringes, the first intermediate layer may contain a surface roughening imparting material. As the surface roughening material, resin particles having a number average particle diameter of 1 μm or more and 5 μm or less are preferable. Examples of the resin particles include curable rubber, polyurethane, epoxy resin, alkyd resin, phenol resin, polyester, silicone resin, and acryl-melamine resin. Further, the first intermediate layer may contain a leveling agent or pigment particles.

  The film thickness of the first intermediate layer is preferably 2 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less.

  In addition, as a device for measuring the film thickness of each layer of the electrophotographic photosensitive member including the first intermediate layer, Fisherscope mms manufactured by Fisher Instruments Co., Ltd. was used.

The volume resistivity of the first intermediate layer is preferably 1.0 × 10 ⁸ Ω · cm or more. Furthermore, the volume resistivity of the first intermediate layer is preferably 1.0 × 10 ¹⁵ Ω · cm or less. Within the above range, the charge flowing through the first intermediate layer at the time of charging / exposure of the electrophotographic photosensitive member does not increase so much that the leakage of the electrophotographic photosensitive member is less likely to occur. More preferably, it is 3.7 × 10 ¹¹ Ω · cm or more and 3.1 × 10 ¹⁴ Ω · cm or less.

  Next, a method for measuring the volume resistivity of the first intermediate layer will be described. FIG. 4A is a top view for explaining a method of measuring the volume resistivity of the first intermediate layer, and FIG. 4B explains a method of measuring the volume resistivity of the first intermediate layer. It is sectional drawing for doing.

  The volume resistivity of the first intermediate layer is measured in a normal temperature and normal humidity environment (temperature 23 ° C. ± 3 ° C., humidity 50% ± 5% RH). A copper tape 203 (manufactured by Sumitomo 3M Limited, model number No. 1181) is attached to the surface of the first intermediate layer 202, and this is used as an electrode on the surface side of the first intermediate layer 202. The support (conductive support) 201 is an electrode on the back surface side of the first intermediate layer 202. A power source 206 for applying a voltage between the copper tape 203 and the support 201 and a current measuring device 207 for measuring a current flowing between the copper tape 203 and the support 201 are installed. In order to apply a voltage to the copper tape 203, first, the copper wire 204 is placed on the copper tape 203. And the copper tape 205 similar to the copper tape 203 is stuck on the copper wire 204 so that the copper wire 204 does not protrude from the copper tape 203, and the copper wire 204 is fixed to the copper tape 203. A voltage is applied to the copper tape 203 using a copper wire 204.

The background current value when no voltage is applied between the copper tape 203 and the support 201 is I ₀ (A), and the current value when a voltage of only a DC voltage (DC component) is applied by −1 V is I ( A). When the film thickness d (cm) of the first intermediate layer 202 and the area of the electrode (copper tape 203) on the surface side of the first intermediate layer 202 are S (cm ² ), the following formula (3) ρ = 1 / (I-I ₀ ) × S / d (Ω · cm) (3)
Is the volume resistivity ρ (Ω · cm) of the first intermediate layer 202.

In this measurement, in order to measure a minute current amount of 1 × 10 ⁻⁶ A or less in absolute value, it is preferable to use a device capable of measuring a minute current as the current measuring device 207. Examples of such a device include a pA meter (trade name: 4140B) manufactured by Yokogawa Hewlett-Packard and a high resistance meter (trade name: 4339B) manufactured by Agilent Technologies.

  The volume resistivity of the first intermediate layer may be measured with a sample in which only the first intermediate layer is formed on the conductive support, and each layer on the first intermediate layer is peeled off from the electrophotographic photosensitive member. And even if it measures by the structure which left only the 1st intermediate | middle layer on the electroconductive support body, the same value is shown.

[Second intermediate layer]
The second intermediate layer in the present invention contains a cured product having electron transport properties. This cured product is a three-dimensional crosslinked product having an electron transporting site as a partial structure. As hardened | cured material which has electron transportability, there exists hardened | cured material obtained by hardening the following compositions. Examples thereof include a composition containing an electron transporting substance having a polymerizable functional group and a crosslinking agent. Furthermore, the composition containing the electron transport substance which has a polymerizable functional group, a crosslinking agent, and resin which has a polymerizable functional group is mentioned.

  The second intermediate layer can be formed as follows. A coating film of the second intermediate layer coating solution containing the above composition is formed, and the coating film is heated and dried to cure (polymerize) the composition, thereby forming a second intermediate layer.

  From the viewpoint of improving the pattern memory, the electron transport material having a polymerizable functional group is a total mass of a composition containing an electron transport material having a polymerizable functional group and a resin having a crosslinking agent and / or a polymerizable functional group. It is preferable that they are 30 mass% or more and 70 mass% or less with respect to.

  The heating temperature for heating and drying the coating film of the second intermediate layer coating solution is preferably 100 to 200 ° C.

[Electron transport material]
As an electron transport substance which comprises the hardened | cured material which has electron transport property, a quinone compound, an imide compound, a benzimidazole compound, a cyclopentadienylidene compound is mentioned, for example. The electron transport material is preferably an electron transport material having a polymerizable functional group. Examples of the polymerizable functional group include a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group. Below, the compound shown by either of following formula (A1)-(A11) is shown as a specific example of an electron transport substance.

In formulas (A1) to (A11), R ^{11 to} R ¹⁶ , R ^{21 to} R ³⁰ , R ^{31 to} R ³⁸ , R ^{41 to} R ⁴⁸ , R ^{51 to} R ⁶⁰ , R ^{61 to} R ⁶⁶ , R ^{71 to} R ^{78, R 81 ~R 90, R} 91 ~R 98 ^is R 101 ^{to R 110 is} R 111 ^{to R 120} each independently represents a monovalent group represented by the following formula (a), a hydrogen atom, a cyano A group, a nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic ring; One of the carbon atoms in the main chain of the alkyl group may be replaced with O, S, NH, or NR ¹²¹ (R ¹²¹ is an alkyl group). The substituent of the substituted alkyl group is an alkyl group, an aryl group, a halogen atom, or an alkoxycarbonyl group. The substituent of the substituted aryl group and the substituent of the substituted heterocyclic group are a halogen atom, a nitro group, a cyano group, an alkyl group, a halogen-substituted alkyl group, and an alkoxy group. Z ²¹ , Z ³¹ , Z ⁴¹ and Z ⁵¹ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. When Z ²¹ is an oxygen atom, R ²⁹ and R ³⁰ do not exist, and when Z ²¹ is a nitrogen atom, R ³⁰ does not exist. When Z ³¹ is an oxygen atom, R ³⁷ and R ³⁸ do not exist, and when Z ³¹ is a nitrogen atom, R ³⁸ does not exist. If Z ⁴¹ is an oxygen atom ^{R 47} and ^{R 48} are ^absent, when ^{Z 41} is a nitrogen atom ^{R 48} is absent. When Z ⁵¹ is an oxygen atom, R ⁵⁹ and R ⁶⁰ do not exist, and when Z ⁵¹ is a nitrogen atom, R ⁶⁰ does not exist.

  In formula (A), at least one of α, β, and γ is a group having a substituent, and the substituent is selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group. At least one group. l and m are each independently 0 or 1, and the sum of l and m is 0 or more and 2 or less.

α is an alkylene group having 1-6 atoms in the main chain, an alkylene group having 1-6 atoms in the main chain substituted with an alkyl group having 1-6 carbon atoms, or a main chain substituted with a benzyl group. An alkylene group having 1 to 6 atoms, an alkylene group having 1 to 6 atoms in the main chain substituted with an alkoxycarbonyl group, or an alkylene group having 1 to 6 atoms in the main chain substituted with a phenyl group . These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkylene group may be replaced with O, S, NR ¹²² (wherein R ¹²² represents a hydrogen atom or an alkyl group).

  β represents a phenylene group, an alkyl-substituted phenylene group having 1 to 6 carbon atoms, a nitro-substituted phenylene group, a halogen-substituted phenylene group, or an alkoxy-substituted phenylene group. These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group as a substituent.

γ represents a hydrogen atom, an alkyl group having 1 to 6 atoms in the main chain, or an alkyl group having 1 to 6 atoms in the main chain substituted with an alkyl group having 1 to 6 carbon atoms. These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group as a substituent. One of the carbon atoms in the main chain of the alkyl group may be replaced with O, S, or NR ¹²³ (wherein R ¹²³ represents a hydrogen atom or an alkyl group).

Among the electron transport materials represented by any of the above formulas (A1) to (A11), at least one of R ^{11 to} R ¹⁶ , at least one of R ^{21 to} R ³⁰ , and at least one of R ^{31 to} R ³⁸ , At least one of R ^{41 to} R ⁴⁸ , at least one of R ^{51 to} R ⁶⁰ , at least one of R ^{61 to} R ⁶⁶ , at least one of R ^{71 to} R ⁷⁸ , at least one of R ^{81 to} R ⁹⁰ , At least one of R ^{91 to} R ⁹⁸ , at least one of R ^{101 to} R ¹¹⁰ , and at least one of R ^{111 to} R ¹²⁰ are made of an electron transport material having a monovalent group represented by the formula (A). preferable.

  Specific examples of the electron transport material having a polymerizable functional group are shown below. In the table, Aa is represented by the same structural formula as A, and specific examples of the monovalent group are shown in the columns of A and Aa. In the table, when γ is “−”, it indicates a hydrogen atom, and the hydrogen atom of γ is included in the structure shown in the column of α or β.

  Derivatives having the structure of (A1) (derivatives of electron transport materials) are disclosed in U.S. Pat. No. 4,442,193, U.S. Pat. No. 4,992,349, U.S. Pat. No. 5,468,583, Chemistry of materials, Vol. 19, no. It is possible to synthesize using a known synthesis method described in 11, 2703-2705 (2007). Moreover, it is possible to synthesize by reaction of naphthalene tetracarboxylic dianhydride and monoamine derivative, which can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc. is there.

The compound represented by (A1) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A1) by introducing a polymerizable functional group into the derivative having the structure (A1) include the following methods. For example, a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A1), a method of introducing a structure having a functional group that can be a polymerizable functional group or a precursor of a polymerizable functional group. is there. As a method to be described later, there is a method of introducing an aryl group having a functional group, for example, based on a halide of a naphthylimide derivative, using, for example, a cross-coupling reaction using a palladium catalyst and a base. Furthermore, there is a method of introducing an alkyl group having a functional group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a naphthylimide derivative. Further, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a halide of a naphthylimide derivative. As a raw material for synthesizing a naphthylimide derivative, there is a method of using a naphthalenetetracarboxylic dianhydride derivative or a monoamine derivative having a polymerizable functional group or a functional group that can be a precursor of the polymerizable functional group.

  The derivative having the structure of (A2) can be purchased from, for example, Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc. Further, based on phenanthrene derivatives or phenanthroline derivatives, Chem. Educator No. 6, 227-234 (2001), Journal of Synthetic Organic Chemistry, vol. 15, 29-32 (1957), Journal of Synthetic Organic Chemistry, vol. 15, 32-34 (1957). It is also possible to introduce a dicyanomethylene group by reaction with malononitrile.

The compound represented by (A2) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A2) by introducing a polymerizable functional group into the derivative having the structure (A2) include the following methods. For example, there is a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A2), or a method of introducing a structure having a polymerizable functional group or a functional group that is a precursor of the polymerizable functional group. . As a method to be described later, for example, there is a method of introducing a functional group-containing aryl group using a cross-coupling reaction using a palladium catalyst and a base based on a halide of phenanthrenequinone. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of phenanthrenequinone. Furthermore, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a halide of phenanthrenequinone.

  The derivative having the structure of (A3) can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc. Also, based on phenanthrene derivatives or phenanthroline derivatives, Bull. Chem. Soc. Jpn. , Vol. 65, 1006-1011 (1992). It is also possible to introduce a dicyanomethylene group by reaction with malononitrile.

The compound represented by (A3) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A3) by introducing a polymerizable functional group into the derivative having the structure (A3) include the following methods. For example, there is a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A3), or a method of introducing a structure having a functional group that becomes a polymerizable functional group or a precursor of a polymerizable functional group. . As a method to be described later, there is a method of introducing a functional group-containing aryl group based on a halide of phenanthroline quinone using, for example, a cross-coupling reaction using a palladium catalyst and a base. Further, there is a method of introducing a functional group-containing alkyl group using a cross coupling reaction using a FeCl ₃ catalyst and a base based on a halide of phenanthroline quinone. Furthermore, there is a method of introducing a hydroxyalkyl group or a carboxyl group based on a halide of phenanthroline quinone after lithiation and then allowing an epoxy compound or CO ₂ to act.

  The derivative having the structure of (A4) can be purchased from, for example, Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc. Moreover, it is also possible to synthesize | combine by the synthesis method of Tetrahedron Letters, 43 (16), 2991-2994 (2002), Tetrahedron Letters, 44 (10), 2087-2091 (2003) based on an acenaphthenequinone derivative. is there. It is also possible to introduce a dicyanomethylene group by reaction with malononitrile.

The compound represented by (A4) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A4) by introducing a polymerizable functional group into the derivative having the structure (A4) include the following methods. For example, after deriving a derivative having the structure of (A4), there are a method of directly introducing a polymerizable functional group, and a method of introducing a polymerizable functional group or a structure having a functional group serving as a precursor of a polymerizable functional group. . As a method to be described later, for example, there is a method of introducing a functional group-containing aryl group using a cross-coupling reaction using, for example, a palladium catalyst and a base based on a halide of acenaphthenequinone. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of acenaphthenequinone. Furthermore, based on the halide of acenaphthenequinone, there is a method of introducing a hydroxyalkyl group or a carboxyl group by allowing an epoxy compound or CO ₂ to act after lithiation.

  The derivative having the structure of (A5) can be purchased from, for example, Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc. Further, it is possible to synthesize using a synthesis method described in US Pat. No. 4,562,132 using a fluorenone derivative and malononitrile. Moreover, it is also possible to synthesize | combine using a fluorenone derivative and an aniline derivative | guide_body using the synthesis method as described in Unexamined-Japanese-Patent No. 5-279582 and Unexamined-Japanese-Patent No. 7-70038.

The compound represented by (A5) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of a method for synthesizing the compound represented by (A5) by introducing a polymerizable functional group into the derivative having the structure (A5) include the following methods. For example, there is a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A5), or a method of introducing a structure having a polymerizable functional group or a functional group serving as a precursor of a polymerizable functional group. . As a method described later, there is a method of introducing a functional group-containing aryl group using, for example, a cross-coupling reaction using a palladium catalyst and a base based on a halide of fluorenone. Further, there is a method of introducing a functional group-containing alkyl group using a cross coupling reaction using a FeCl ₃ catalyst and a base based on a halide of fluorenone. Furthermore, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a halide of fluorenone.

  The derivative having the structure (A6) can be synthesized by using a synthesis method described in Chemistry Letters, 37 (3), 360-361 (2008), Japanese Patent Application Laid-Open No. 9-151157, for example. Moreover, it can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc.

The compound represented by (A6) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A6) by introducing a polymerizable functional group into the derivative having the structure (A6) include the following methods. For example, after synthesizing the derivative having the structure of (A6), there are a method of directly introducing a polymerizable functional group, and a method of introducing a polymerizable functional group or a structure having a functional group that is a precursor of the polymerizable functional group. . As a method to be described later, for example, there is a method of introducing a functional group-containing aryl group using a cross-coupling reaction using, for example, a palladium catalyst and a base based on a halide of naphthoquinone. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a naphthoquinone halide. Furthermore, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a naphthoquinone halide.

  Derivatives having the structure (A7) are disclosed in JP-A-1-206349, PPCI / Japan Hard Copy '98 Preliminary Collection p. 207 (1998) can be used for the synthesis. Moreover, it is possible to synthesize | combine as a raw material the phenol derivative which can be purchased from Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Japan Co., Ltd.

The compound represented by (A7) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A7) by introducing a polymerizable functional group into the derivative having the structure (A7) include the following methods. For example, there is a method of synthesizing a derivative having the structure of (A7) and then introducing a structure having a polymerizable functional group or a functional group that becomes a precursor of the polymerizable functional group. As this method, for example, there is a method of introducing a functional group-containing aryl group using a cross coupling reaction using, for example, a palladium catalyst and a base based on a halide of diphenoquinone. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a diphenoquinone halide. Further, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a diphenoquinone halide.

  Derivatives having the structure (A8) are described in, for example, Journal of the American chemical society, Vol. 129, no. 49, 15259-78 (2007), and can be synthesized using a known synthesis method. Moreover, it is possible to synthesize by reaction of perylenetetracarboxylic dianhydride which can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd. or Johnson Matthey Japan Inc. and a monoamine derivative. .

The compound represented by (A8) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A8) by introducing a polymerizable functional group into the derivative having the structure (A8) include the following methods. For example, a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A8), a method of introducing a structure having a functional group that can be a polymerizable functional group or a precursor of a polymerizable functional group. is there. As a method described later, for example, there is a method using a cross-coupling reaction using, for example, a palladium catalyst and a base based on a halide of a perylene imide derivative. Furthermore, there is a method of using a cross coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a perylene imide derivative. As a raw material for synthesizing a perylene imide derivative, there is a method of using a perylene tetracarboxylic dianhydride derivative or a monoamine derivative having a polymerizable functional group or a functional group that can be a precursor of the polymerizable functional group.

  The derivative having the structure of (A9) can be purchased from, for example, Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd., or Johnson Matthey Japan Inc.

The compound represented by (A9) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A9) by introducing a polymerizable functional group into the derivative having the structure (A9) include the following methods. For example, there is a method of introducing a structure having a polymerizable functional group or a functional group serving as a precursor of the polymerizable functional group into the derivative having the structure of (A9). As this method, for example, there is a method of introducing a functional group-containing aryl group using a cross-coupling reaction using, for example, a palladium catalyst and a base based on an anthraquinone halide. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using an FeCl ₃ catalyst and a base based on an anthraquinone halide. Furthermore, based on the anthraquinone halide, there is a method of introducing a hydroxyalkyl group or a carboxyl group by allowing an epoxy compound or CO ₂ to act after lithiation.

  The derivative having the structure of (A10) can be synthesized as follows using a known synthesis method described in Japanese Patent No. 3717320, for example. That is, it can be synthesized by oxidizing a phenol derivative having a hydrazone structure with an appropriate oxidizing agent such as potassium permanganate in an organic solvent. This phenol derivative having a hydrazone structure condenses, for example, a phenyl hydrazine derivative that can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. or Johnson Matthey Japan Incorporated, and a hydroxybenzaldehyde derivative. It can be synthesized.

The compound represented by (A10) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of the method for synthesizing the compound represented by (A10) by introducing a polymerizable functional group into the derivative having the structure (A10) include the following methods. For example, after synthesizing a derivative having the structure of (A10), there is a method of introducing a polymerizable functional group or a structure having a functional group that becomes a precursor of the polymerizable functional group. As this method, for example, based on a halide of a phenol derivative having a hydrazone structure, there is a method of introducing a functional group-containing aryl group using, for example, a cross-coupling reaction using a palladium catalyst and a base. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a phenol derivative having a hydrazone structure. Furthermore, there is a method of introducing a hydroxyalkyl group or a carboxyl group based on a halide of a phenol derivative having a hydrazone structure, after lithiation, by allowing an epoxy compound or CO ₂ to act.

  The derivative having the structure (A11) can be synthesized by using a known synthesis method described in, for example, JP-A-2007-108670 and Journal of Imaging Society of Japan 45 (6), 521-525, (2006). is there. It is also possible to synthesize by reaction of naphthalene tetracarboxylic dianhydride, monoamine derivative and hydrazine which can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd. or Johnson Matthey Japan Inc. It is.

The compound represented by (A11) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. Examples of methods for synthesizing the compound represented by (A11) by introducing a polymerizable functional group into the derivative having the structure of (A11) include the following methods. For example, a method of directly introducing a polymerizable functional group after synthesizing a derivative having the structure of (A11), a method of introducing a structure having a functional group that can be a polymerizable functional group or a precursor of a polymerizable functional group. is there. As a method described later, there is a method of introducing a functional group-containing aryl group using, for example, a cross-coupling reaction using a palladium catalyst and a base based on a halide of a naphthylimide derivative. Furthermore, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a naphthylimide derivative. Further, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO ₂ after lithiation based on a halide of a naphthylimide derivative.

  The electron transport material having a polymerizable functional group preferably has two or more polymerizable functional groups in the same molecule.

[Crosslinking agent]
Next, the crosslinking agent will be described.

As the crosslinking agent, it is possible to use an electron transport material having a polymerizable functional group and a compound that polymerizes or crosslinks with a resin having a polymerizable functional group. Specifically, compounds described in Shinzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981) can be used. For example, an isocyanate compound or an amine compound is preferable. More preferably, it is a crosslinking agent (isocyanate compound, amine compound) having 3 to 6 monovalent groups represented by an isocyanate group, a blocked isocyanate group, or —CH ₂ —OR ¹ .

  The isocyanate compound is preferably an isocyanate compound having 3 to 6 isocyanate groups or blocked isocyanate groups. Moreover, it is preferable that the molecular weight of an isocyanate compound is the range of 200-1300.

The blocked isocyanate group is a group having a structure of —NHCOX ¹ (X ¹ is a protecting group). X ¹ may be any protecting group that can be introduced into an isocyanate group, but groups represented by the following formulas (H1) to (H7) are more preferable.

  Examples of the isocyanate compound include triisocyanate benzene, triisocyanate methylbenzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate. 2,2,4-trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanate hexanoate, norbornane diisocyanate modified isocyanurate, biuret, allophanate, trimethylolpropane and pentaerythritol Adduct modified It is.

  Below, the specific example of an isocyanate compound is shown.

  As the amine compound, a compound represented by any one of the following formulas (C1) to (C5) or an oligomer of a compound represented by any one of the following formulas (C1) to (C5) is preferable. Moreover, as a molecular weight of those compounds, the range of 200-1000 is preferable. More preferably, it is a melamine compound represented by the formula (C1) or a guanamine compound represented by the formula (C2).

In formulas (C1) to (C5), R ^{11 to} R ¹⁶ , R ^{22 to} R ²⁵ , R ^{31 to} R ³⁴ , R ^{41 to} R ⁴⁴ , and R ^{51 to} R ⁵⁴ are each independently a hydrogen atom, hydroxy A monovalent group represented by a group, an acyl group, or CH ₂ —OR ¹ ; At least one of R ^{11 to} R ¹⁶ , at least one of R ^{22 to} R ²⁵ , at least one of R ^{31 to} R ³⁴ , at least one of R ^{41 to} R ⁴⁴ , and at least one of R ^{51 to} R ⁵⁴ Is a monovalent group represented by —CH ₂ —OR ¹ . R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. As the alkyl group, a methyl group, an ethyl group, a propyl group (n-propyl group, iso-propyl group), and a butyl group (n-butyl group, iso-butyl group, tert-butyl group) are preferable from the viewpoint of polymerizability. . R ²¹ represents an aryl group, an alkyl group-substituted aryl group, a cycloalkyl group, or an alkyl group-substituted cycloalkyl group.

  Specific examples of the compound represented by any one of formulas (C1) to (C5) are shown below. Moreover, you may contain the oligomer (multimer) of the compound shown by either of Formula (C1)-(C5). The above oligomers and monomers can be used in combination of two or more.

  Examples of the compound represented by the formula (C1) include Super Melami No. 90 (manufactured by NOF Corporation), Super Becamine (R) TD-139-60, L-105-60, L127-60, L110-60, J-820-60, G-821-60 (manufactured by DIC) Uban 2020 (Mitsui Chemicals), Sumitex Resin M-3 (Sumitomo Chemical Co., Ltd.), Nicalak MW-30, MW-390, MX-750LM (Nippon Carbide). Examples of the compound represented by the formula (C2) include “Super Becamine (R) L-148-55, 13-535, L-145-60, TD-126 (manufactured by DIC), Nicalac BL-60, BX-4000 (manufactured by Nippon Carbide Co., Ltd.) Examples of the compound represented by the formula (C3) include Nicarak MX-280 (manufactured by Nippon Carbide Co., Ltd.) The compound represented by the formula (C4) Examples include Nicalac MX-270 (manufactured by Nippon Carbide Co., Ltd.) Examples of the compound represented by the formula (C5) include Nicalac MX-290 (manufactured by Nippon Carbide Co., Ltd.).

〔resin〕
Next, the resin having a polymerizable functional group will be described. Examples of the resin having a polymerizable functional group include a resin having a structural unit represented by the following formula (D).

In the formula, R ⁶¹ represents a hydrogen atom or an alkyl group. Y ¹ represents a single bond, an alkylene group or a phenylene group. W ¹ represents a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group.

  Examples of the resin having the structural unit represented by the formula (D) include an acetal resin, a polyolefin resin, a polyester resin, a polyether resin, and a polyamide resin. Such a resin has the following characteristic structure in addition to the structural unit represented by the above formula (D). Characteristic structures are shown in (E-1) to (E-5) below. (E-1) is a structural unit of an acetal resin. (E-2) is a structural unit of polyolefin resin. (E-3) is a structural unit of a polyester resin. (E-4) is a structural unit of a polyether resin. (E-5) is a structural unit of polyamide resin.

In the above ^formula, R 201 ^{to R 205} each independently represent a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ^{206 to} R ²¹⁰ each independently represent a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group. When R ²⁰¹ is C ₃ H _7, it is represented as butyral.

  A resin having a structural unit represented by the formula (D) (hereinafter also referred to as “resin D”) is, for example, a monomer having a polymerizable functional group that can be purchased from Sigma-Aldrich Japan Co., Ltd. or Tokyo Chemical Industry Co., Ltd. Can be obtained by polymerizing.

  Examples of the resin that can be purchased include polyether polyol resins such as AQD-457 and AQD-473 manufactured by Nippon Polyurethane Industry Co., Ltd., Sannics GP-400 and GP-700 manufactured by Sanyo Chemical Industries; Hitachi Chemical Phthalkid W2343 manufactured by Co., Ltd., watersol S-118 manufactured by DIC Co., Ltd., CD-520, beccolite M-6402-50, M-6201-40IM, Hallidip WH-1188 manufactured by Harima Kasei Co., Ltd. Polyester polyol resins such as ES3604 and ES6538 manufactured by DIC Corporation; Polyacryl polyol resins such as Vernock WE-300 and WE-304 manufactured by DIC Corporation; Polyvinyl alcohol resins such as Kuraray Poval PVA-203 manufactured by Kuraray Co., Ltd .; Sekisui Chemical BX-1 manufactured by Kogyo Co., Ltd. Polyvinyl acetal resin such as M-1; Polyamide resin such as Toraysin FS-350 manufactured by Nagase ChemteX Corp .; Carboxyl group-containing resin such as Aqualic manufactured by Nippon Shokubai Co., Ltd., Finelex SG2000 manufactured by Lead City Co., Ltd .; DIC Examples include polyamine resins such as racamide, manufactured by Co., Ltd .; polythiol resins such as QE-340M manufactured by Toray Industries, Inc. Among these, polyvinyl acetal resins and polyester polyol resins are more preferable from the viewpoints of polymerizability and uniformity of the undercoat layer.

  The weight average molecular weight (Mw) of the resin D is more preferably 5,000 to 400,000.

  Examples of the quantitative method for the polymerizable functional group in the resin include the following methods. Titration of carboxyl group using potassium hydroxide, titration of amino group using sodium nitrite, titration of hydroxy group using acetic anhydride and potassium hydroxide, 5,5′-dithiobis (2-nitrobenzoic acid) There is a titration of the thiol groups used. Furthermore, a calibration curve method obtained from an IR spectrum of a sample in which the polymerizable functional group introduction ratio is changed can also be mentioned.

  Table 12 below shows specific examples of the resin D. In Table 12, the “characteristic structure” column indicates the structural unit represented by any one of (E-1) to (E-5) above.

  The thickness of the second intermediate layer is preferably 0.1 μm or more and 1.5 μm or less, more preferably 0.2 μm or more and 0.7 μm or less from the viewpoint of suppressing the retention of electrons and further improving the pattern memory. The second intermediate layer may contain roughened particles as an additive. Examples of roughening particles include curable resin particles and metal oxide particles. Moreover, you may contain additives, such as a silicone oil, surfactant, and a silane compound.

  Examples of the solvent used in the second intermediate layer coating solution include alcohol solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone solvents, ketone alcohol solvents, ether solvents, ester solvents. Is mentioned.

[Conductive support]
As the conductive support, for example, a conductive support formed of a metal or alloy such as aluminum, nickel, copper, gold, or iron can be used. A support formed by a thin film of aluminum, silver or gold metal on an insulating support such as polyester resin, polycarbonate resin, polyimide resin or glass, or a support formed by a thin film of conductive material such as indium oxide or tin oxide. Can be mentioned.

  The surface of the conductive support may be subjected to electrochemical treatment such as anodization, wet honing treatment, blast treatment, or cutting treatment in order to improve electrical characteristics and suppress interference fringes.

[First intermediate layer, second intermediate layer]
The first intermediate layer and the second intermediate layer are as described above.

(Charge generation layer)
A charge generation layer is formed on the second intermediate layer.

  Examples of charge generating materials include azo pigments, perylene pigments, anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives, isoviolanthrone derivatives, indigo derivatives, thioindigo derivatives, phthalocyanine pigments, and bisbenzimidazoles. Derivatives. Among these, azo pigments and phthalocyanine pigments are preferable. Among the phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine, and hydroxygallium phthalocyanine are preferable.

  Examples of the binder resin used for the charge generation layer include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic ester, methacrylic ester, vinylidene fluoride, and trifluoroethylene, polyvinyl Examples include alcohol resins, polyvinyl acetal resins, polycarbonate resins, polyester resins, polysulfone resins, polyphenylene oxide resins, polyurethane resins, cellulose resins, phenol resins, melamine resins, silicon resins, and epoxy resins. Among these, polyester resin, polycarbonate resin, and polyvinyl acetal resin are preferable, and polyvinyl acetal is more preferable.

  The charge generation layer is preferably formed by forming a coating film of a coating solution for a charge generation layer obtained by dispersing a charge generation material together with a binder resin and a solvent, and drying the obtained coating film. The charge generation layer may be a vapor generation film of a charge generation material.

  In the charge generation layer, the mass ratio of the charge generation material to the binder resin (charge generation material / binder resin) is preferably in the range of 10/1 to 1/10, and is preferably 5/1 to 1/5. A range is more preferable. Examples of the solvent used in the charge generation layer coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  The thickness of the charge generation layer is preferably 0.05 μm or more and 5 μm or less.

(Hole transport layer)
A hole transport layer is formed on the charge generation layer.

  Examples of the hole transport material include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds, triarylamine compounds, and triphenylamine. Alternatively, examples of the hole transport material include polymers having groups derived from these compounds in the main chain or side chain. Among these, a triarylamine compound, a benzidine compound, and a styryl compound are preferable.

  Examples of the binder resin used for the hole transport layer include polyester resins, polycarbonate resins, polymethacrylate resins, polyarylate resins, polysulfone resins, and polystyrene resins. Among these, polycarbonate resin and polyarylate resin are preferable. Moreover, as these molecular weights, weight average molecular weight (Mw) = 10,000-300,000 is preferable.

  In the hole transport layer, the mass ratio of the hole transport material to the binder resin (hole transport material / binder resin) is preferably 10/5 to 5/10, and more preferably 10/8 to 6/10. .

  The thickness of the hole transport layer is preferably 3 μm or more and 40 μm or less, and more preferably 5 μm or more and 16 μm or less. Examples of the solvent used in the hole transport layer coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  A protective layer may be formed on the hole transport layer. The protective layer preferably contains conductive particles or a charge transport material and a binder resin. The protective layer may further contain an additive such as a lubricant. In addition, the binder resin itself may have conductivity and charge transport property, and in that case, the protective layer may not contain conductive particles or a charge transport material in addition to the binder resin. The binder resin of the protective layer may be a thermoplastic resin or a curable resin obtained by polymerization with heat, light, or radiation (electron beam). The thickness of the protective layer is preferably 1 μm or more and 10 μm or less.

  As a method of forming each layer, a coating film obtained by dissolving and / or dispersing materials constituting each layer in a solvent is applied to form a coating film, and the resulting coating film is dried and / or cured. The method of forming by making it preferable is preferable. Examples of the method for applying the coating solution include a dip coating method (dip coating method), a spray coating method, a curtain coating method, and a spin coating method.

[Process cartridge and electrophotographic apparatus]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge provided with an electrophotographic photosensitive member.

  The electrophotographic apparatus shown in FIG. 1 has a cylindrical electrophotographic photosensitive member 1 and is driven to rotate about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. The surface (circumferential surface) of the electrophotographic photosensitive member 1 that is driven to rotate is charged to a predetermined positive or negative potential by a charging unit 3 (primary charging unit: charging roller). Next, exposure is performed with exposure light (image exposure light) 4 from an exposure means (not shown) such as slit exposure or laser beam scanning exposure. Thus, an electrostatic latent image corresponding to the target image is formed on the surface of the electrophotographic photoreceptor 1.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in the developer of the developing means 5 to form a toner image. Next, the toner image formed on the surface of the electrophotographic photoreceptor 1 is sequentially transferred onto the transfer material (paper) P by the transfer bias from the transfer means (transfer roller) 6. The transfer material P is taken out from the transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1 and fed. Is done.

  The transfer material P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 1 and introduced into the fixing means 8 to receive the image fixing, and is printed out as an image formed product (print, copy). Is done.

  The surface of the electrophotographic photosensitive member 1 after the toner image is transferred is cleaned by a cleaning means (cleaning blade) 7 after removal of the transfer residual developer (transfer residual toner). Next, after being subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), it is repeatedly used for image formation. As shown in FIG. 1, when the charging unit 3 is a contact charging unit using a charging roller, pre-exposure is not always necessary.

  Among the constituent elements such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7, a plurality of components are selected and placed in a container and integrally coupled as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 1, an electrophotographic photosensitive member 1, a charging unit 3, a developing unit 5, and a cleaning unit 7 are integrally supported to form a cartridge, and an electrophotographic apparatus is provided using a guide unit 10 such as a rail of the electrophotographic apparatus main body. The process cartridge 9 is detachable from the main body.

(Synthesis Example 1)
26.8 g (100 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 150 ml of dimethylacetamide were added to a 300 ml three-necked flask under a nitrogen stream at room temperature. To this, a mixture of 8.9 g (100 mmol) of butanolamine and 25 ml of dimethylacetamide was added dropwise with stirring. After completion of the dropwise addition, the mixture was heated to reflux for 6 hours. After heating and refluxing, the container was cooled and concentrated under reduced pressure. Ethyl acetate was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the purified product was recrystallized with ethyl acetate / hexane to obtain 10.2 g of a monoimide body in which a butanol structure was introduced only on one side.

  A 300 ml three-necked flask was charged with 6.8 g (20 mmol) of the above monoimide, 1 g (20 mmol) of hydrazine monohydrate, 10 mg of p-toluenesulfonic acid, and 50 ml of toluene, and heated to reflux for 5 hours. After heating and refluxing, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Further, the purified product was recrystallized from toluene / ethyl acetate to obtain 2.54 g of a compound (electron transport material) represented by (A1101).

(Synthesis Example 2)
In a 500 ml three-necked flask under a nitrogen stream at room temperature, 23.4 g (100 mmol) of the compound represented by the following formula (X-1) and 15.2 g (100 mmol) of the compound represented by the following formula (X-2) were added to tetrahydrofuran. Dissolved in 200 ml. Next, after heating to 60 ° C., the mixture was heated to reflux for 6 hours. After completion of heating and refluxing, the vessel was cooled, and then the reaction solution was filtered, and the filtrate was concentrated to obtain 30 g of crude crystals. The obtained crystal was recrystallized from acetone, and the crystal was dried under reduced pressure to obtain 25.8 g of a compound represented by the following formula (X-3). In addition, 3,5-di-tert-butyl-4-hydroxybenzaldehyde manufactured by Tokyo Chemical Industry Co., Ltd. was used as the compound represented by the formula (X-1). Moreover, 4-hydrazinobenzoic acid made from Sigma-Aldrich Japan Co., Ltd. was used as the compound represented by the formula (X-2).

  Next, after 23.2 g (63 mmol) of the compound represented by the formula (X-3) was dissolved in 200 ml of chloroform in a 500 ml three-necked flask, 18.5 g (117 mmol) of potassium permanganate was added. This was heated to 52 ° C. and stirred at that temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated to obtain 25.6 g of crude crystals. The obtained crystal was recrystallized from acetone, and the crystal was dried under reduced pressure to obtain 22.0 g of a compound represented by the following formula (X-4).

  In a 500 ml three-necked flask, 18.3 g (50 mmol) of the compound represented by the formula (X-4) was dissolved in 200 ml of tetrahydrofuran, and then 1.89 g (50 mmol) of sodium borohydride and 11.7 g (50 mmol) of zirconium chloride. Was added. This was heated to 52 ° C. and stirred at that temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated to obtain 15.3 g of crude crystals. The obtained crystals were recrystallized from acetone, and the crystals were dried under reduced pressure to obtain 14.1 g of the exemplified compound (A1001).

  Next, a preparation example of the first intermediate layer coating solution for forming the first intermediate layer will be described. “Part” means “part by mass”.

(First intermediate layer coating solution 1)
100 parts of zinc oxide particles (manufactured by Teika Co., Ltd., average particle size: 70 nm, specific surface area value: 15 m ² / g) are stirred and mixed with 500 parts of toluene, and N-2- (aminoethyl) -3-amino 1.25 parts of propyltrimethoxysilane (trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 2 hours. Then, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain zinc oxide particles M1 surface-treated with a silane coupling agent.

  Next, 15 parts of a polyvinyl acetal resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and 13.5 parts of a blocked isocyanate compound (trade name: Sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) Was dissolved in 85 parts of methyl ethyl ketone. To this solution, 60 parts of zinc oxide particles M1 and 0.6 part of 1,2-dihydroxyanthraquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) are added, and this is added to a sand mill apparatus using glass beads having a diameter of 1 mm at a temperature of 23 ± 3 ° C. Dispersed for 4 hours below. After dispersion, 0.005 part of dioctyltin dilaurate (catalyst) as a catalyst and 4.0 parts of silicone resin particles (trade name: Tospearl 145, manufactured by Momentive Performance Materials Co., Ltd.) were added and stirred. A coating solution 1 for the first intermediate layer was prepared.

(First intermediate layer coating solution 2)
The coating for the first intermediate layer, except that the zinc oxide particles in the coating liquid 1 for the first intermediate layer were changed to titanium oxide particles (trade name: CR-EL, manufactured by Ishihara Sangyo Co., Ltd., average particle size: 250 nm). In the same manner as described in Liquid 1, titanium oxide particles N1 that were surface-treated with a silane coupling agent were obtained.

  Next, 6 parts of alkyd resin (trade name: Beckolite M-6401-50, manufactured by Dainippon Ink & Chemicals, Inc.) and melamine resin (trade name: Super Becamine G-821-60, Dainippon Ink Chemical Co., Ltd.) 4 parts of Kogyo Co., Ltd. were dissolved in 50 parts of 2-butanone. 60 parts of titanium oxide particles N1 were added to this solution and dispersed for 1 hour in a sand mill apparatus using zirconia bead beads having a diameter of 2 mm in an atmosphere of 23 ± 3 ° C. to prepare a first intermediate layer coating solution 2.

(First intermediate layer coating solution 3)
100 parts of titanium oxide particles (CR-EL) were stirred and mixed with 500 parts of toluene, and 1.25 parts of 1-aminododecane (manufactured by Sigma-Aldrich) were added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain titanium oxide particles N2 surface-treated with a compound having an amino group.

  Next, a first intermediate layer coating solution 3 was prepared in the same manner as the first intermediate layer coating solution 2 except that the titanium oxide particles N2 were used as the metal oxide particles.

(First intermediate layer coating solution 4)
100 parts of titanium oxide particles (CR-EL) were stirred and mixed with 500 parts of toluene, and 1.25 parts of 1,2-epoxydodecane (manufactured by Sigma-Aldrich) were added and stirred for 2 hours. Then, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain titanium oxide particles N3 surface-treated with a compound having an epoxy group.

  Next, a first intermediate layer coating solution 4 was prepared in the same manner as the first intermediate layer coating solution 2 except that the titanium oxide particles N3 were used as the metal oxide particles.

(First intermediate layer coating solution 5)
100 parts of titanium oxide particles (CR-EL) were stirred and mixed with 500 parts of toluene, and 1.25 parts of undecanoic acid (manufactured by Sigma-Aldrich) were added and stirred for 2 hours. Then, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain titanium oxide particles N4 surface-treated with a compound having a carboxyl group.

  Next, a first intermediate layer coating solution 5 was prepared in the same manner as the first intermediate layer coating solution 2 except that titanium oxide particles N4 were used as the metal oxide particles.

(First intermediate layer coating solution 6)
100 parts of titanium oxide particles (CR-EL) were stirred and mixed with 500 parts of toluene, and 1.25 parts of 1-hexadecanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain titanium oxide particles N5 surface-treated with a compound having a hydroxy group.

  Next, a first intermediate layer coating solution 6 was prepared in the same manner as the first intermediate layer coating solution 2 except that titanium oxide particles N5 were used as the metal oxide particles.

(First intermediate layer coating solution 7)
100 parts of titanium oxide particles (CR-EL) were stirred and mixed with 500 parts of toluene, 1.25 parts of 1-dodecanethiol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain titanium oxide particles N6 surface-treated with a compound having a thiol group.

  Next, a first intermediate layer coating solution 7 was prepared in the same manner as the first intermediate layer coating solution 2 except that the titanium oxide particles N6 were used as the metal oxide particles.

(First intermediate layer coating solution 8)
A first intermediate layer coating solution 8 was prepared in the same manner as in the first intermediate layer coating solution 1 except that 1,2-dihydroxyanthraquinone was not included.

(First intermediate layer coating solution 9)
A first intermediate layer coating solution 9 was prepared in the same manner except that 45 parts of zinc oxide particles M1 were used as metal oxide particles in the first intermediate layer coating solution 1.

(First intermediate layer coating solution 10)
A first intermediate layer coating solution 10 was prepared in the same manner as in the first intermediate layer coating solution 1, except that 70 parts of zinc oxide particles M1 were used as metal oxide particles.

(First intermediate layer coating solution 11)
100 parts of zinc oxide particles (manufactured by Teika, average particle size: 70 nm, specific surface area value: 15 m ² / g) are stirred and mixed with 500 parts of toluene, and 3-methacryloxypropyltrimethoxysilane (trade name: KBM503, 1.25 parts of Shin-Etsu Chemical Co., Ltd.) was added and stirred for 2 hours. Then, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain zinc oxide particles M2 surface-treated with a silane coupling agent.

  Next, a first intermediate layer coating solution 11 was prepared in the same manner as the first intermediate layer coating solution 1 except that the zinc oxide particles M2 were used as the metal oxide particles.

(First intermediate layer coating solution 12)
100 parts of zinc oxide particles (Taika, average particle size: 70 nm, specific surface area value: 15 m ² / g) are stirred and mixed with 500 parts of toluene, and p-styryltrimethoxysilane (trade name: KBM1403, Shin-Etsu Chemical). 1.25 parts of Kogyo Co., Ltd.) was added and stirred for 2 hours. Then, toluene was distilled off under reduced pressure and baked at a temperature of 120 ° C. for 3 hours to obtain zinc oxide particles M3 surface-treated with a silane coupling agent.

  Next, a first intermediate layer coating solution 12 was prepared in the same manner as the first intermediate layer coating solution 1 except that the zinc oxide particles M3 were used as the metal oxide particles.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In the examples, “part” means “part by mass”.

Example 1
An aluminum cylinder (JIS-A3003) having a diameter of 30 mm was used as the conductive support.

  Next, the first intermediate layer coating solution 1 is dip coated on the conductive support to form a coating film, and the resulting coating film is dried at a temperature of 180 ° C. for 40 minutes, whereby the film thickness is 20 μm. A first intermediate layer was formed.

Next, 4 parts of the electron transport material (A101), 5.5 parts of the crosslinking agent [B1: protecting group (H1) = 5.1: 2.2 (mass ratio)], 0.3 parts of the resin (D1) Part of the catalyst (dioctyltin laurate) was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured (polymerized). A second intermediate layer of 0.26 μm was formed. Thus, the laminated body which has an electroconductive support body, a 1st intermediate | middle layer, and a 2nd intermediate | middle layer was formed. The content of the electron transport material with respect to the total mass of the electron transport material, the crosslinking agent, and the resin was 41% by mass. In the resin (D1), in formula (E-1) which is a butyral having a characteristic structure, R ²⁰¹ represents C ₃ H ₇ .

  Next, Bragg angles (2θ ± 0.2 °) of CuKα characteristic X-ray diffraction of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 10 parts of a hydroxygallium phthalocyanine crystal (charge generation material) having a peak at 28.3 ° was prepared. This charge generating substance, 0.1 part of a compound represented by the following formula (17), 5 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone The mixture was placed in a sand mill using 0.8 mm glass beads and dispersed for 1.5 hours. Next, 250 parts of ethyl acetate was added to the dispersion to prepare a charge generation layer coating solution. The charge generation layer coating solution is dip-coated on the second intermediate layer to form a coating film, and the resulting coating film is dried at a temperature of 100 ° C. for 10 minutes, whereby a film thickness of 0.15 μm is obtained. A generation layer was formed.

  Next, 4 parts each of a compound represented by the following formula (9-1) and a compound represented by the following formula (9-2), and a bisphenol Z-type polycarbonate (trade name: Z400, Mitsubishi Engineering Plastics Co., Ltd.) )) Was dissolved in a mixed solvent of 40 parts of dimethoxymethane and 60 parts of chlorobenzene to prepare a coating solution for a hole transport layer. This hole transport layer coating solution is dip-coated on the charge generation layer to form a coating film, and the resulting coating film is dried at a temperature of 120 ° C. for 40 minutes, thereby transporting a hole with a thickness of 15 μm. A layer was formed.

  In this manner, a laminate and an electrophotographic photoreceptor for pattern memory evaluation having a charge generation layer and a hole transport layer on the laminate were produced. Further, another electrophotographic photosensitive member was produced in the same manner as described above, and used as an electrophotographic photosensitive member for determination.

(Judgment test)
The electrophotographic photosensitive member for determination was immersed in a mixed solvent of 40 parts of dimethoxymethane and 60 parts of chlorobenzene for 5 minutes, ultrasonic waves were applied, and the hole transport layer was peeled off. Next, the charge generation layer was polished using a wrapping tape (C2000: manufactured by Fuji Photo Film Co., Ltd.). Then, the laminated body which has a conductive support body, a 1st intermediate | middle layer, and a 2nd intermediate | middle layer was produced by drying at the temperature of 100 degreeC for 10 minutes, and it was set as the electrophotographic photoreceptor for determination. Using the FTIR-ATR method, it was confirmed that the components of the hole transport layer and the charge generation layer were not detected on the surface.

  Next, in the above laminate, a measurement part is cut into 2 cm (circumferential direction of the electrophotographic photosensitive member) × 4 cm (long axis direction of the electrophotographic photosensitive member), and a film is formed on the surface of the second intermediate layer by vapor deposition. A circular gold electrode having a thickness of 300 nm and a diameter of 12 mm was produced. This was used as a measurement sample.

Next, this sample was allowed to stand for 24 hours in an environment of a temperature of 23 ° C. and a humidity of 50% RH, and then the above-described determination method was used. First, the entire sample was shielded from room light using a dark screen. Next, while applying a DC electric field of 0 V from the conductive support to the gold electrode, an AC electric field of 3.0 × 10 ⁻³ V / μm was applied between the conductive support and the gold electrode, and from 1 MHz The impedance was measured by sweeping the frequency up to 0.1 Hz. Thus, the impedance (R_0V) measured by applying an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz while applying a DC electric field of 0 V was measured.

Next, a DC electric field of −0.3 V / μm is applied from the conductive support to the gold electrode with respect to the total thickness of the first intermediate layer and the second intermediate layer. While applying this DC electric field, an AC electric field of 3.0 × 10 ⁻³ V / μm is applied between the conductive support and the gold electrode, and a frequency from 1 MHz to 0.1 Hz is swept to perform impedance. It was measured. Thus, while applying a DC electric field of −0.3 V / μm per unit thickness of the total thickness of the first intermediate layer and the second intermediate layer, 3.0 × 10 ⁻³ V / μm, And the impedance (R_nV) measured by applying an alternating electric field of 0.1 Hz was measured. R_nV / R_0V was calculated from the obtained R_0V and R_nV. Table 17 shows the measurement results.

(Evaluation of pattern memory)
The manufactured electrophotographic photosensitive member for evaluation was mounted on a laser beam printer (trade name: LBP-2510) manufactured by Canon Inc. for evaluation. Details are as follows.

  The produced electrophotographic photosensitive member was mounted on the laser beam printer. This was installed in a low-temperature and low-humidity environment (temperature 15 ° C./humidity 10% RH), and an image of a vertical line pattern of 3 dots and 100 spaces was repeatedly output 15000 images. After that, 4 types of halftone images and solid black images are output, and these output images are ranked into 6 as shown in Table 13 according to the appearance of vertical stripes that are the history of vertical lines of 3 dots and 100 spaces. Divided. The better the pattern memory, the higher the rank number. The four halftones are the halftone of the 1-dot Keima pattern, the halftone of the horizontal line of 1 dot and 1 space, the halftone of the horizontal line of 2 dots and 3 spaces, and the halftone of the horizontal line of 1 dot and 2 spaces. is there.

(Leak evaluation)
Further, leakage was evaluated as follows using the produced electrophotographic photosensitive member for evaluation.

The produced electrophotographic photosensitive member was mounted on the above-mentioned laser beam printer manufactured by Canon Inc. This was installed in a low-temperature and low-humidity environment (temperature: 15 ° C./humidity: 10% RH), and an image of a vertical line pattern with 3 dots and 100 spaces was repeatedly output 15000 images. One half-tone image of a 1-dot Keima pattern was output at the time when the above-mentioned 15000-sheet repeated image output was started, and after 7500-sheet image output was completed and after 15000-sheet image output was completed. The halftone images of the 1-dot Keima pattern were visually ranked into five according to the following criteria. The results are shown in Table 17. The criteria for image evaluation are as follows.
A: Image defect due to occurrence of leak in image is not observed B: Small black spot due to occurrence of leak is slightly observed in image C: Large black spot due to occurrence of leak in image is clearly observed D: Leak in image Large black spots and short horizontal black streaks due to occurrence are observed E: Long horizontal black streaks due to occurrence of leaks are observed in the image.

(Example 2)
The first intermediate layer coating solution 2 is dip-coated on the conductive support to form a coating film, and the resulting coating film is dried at a temperature of 180 ° C. for 40 minutes, whereby the film thickness is 3.5 μm. An intermediate layer was formed. Otherwise, an electrophotographic photoreceptor was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 17.

(Examples 3 to 12)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the type and film thickness of the first intermediate layer coating solution were changed as shown in Table 14, and evaluated in the same manner. The results are shown in Table 17.

(Examples 13 to 15)
Example 2 except that the thickness of the second intermediate layer was changed from 0.53 μm to 0.35 μm (Example 13), 0.50 μm (Example 14), and 1.05 μm (Example 15). Thus, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1. The results are shown in Table 17.

(Examples 16 to 25)
Example 1 except that the electron transport material (A101) in the second intermediate layer of Example 1 was changed to the electron transport material shown in Table 14 and the film thickness of the second intermediate layer was changed as shown in Table 14. In the same manner as in Example 1, an electrophotographic photoreceptor was produced and evaluated in the same manner. The results are shown in Table 17.

(Example 26)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  5 parts of the electron transport material (A101), 1.75 parts of the amine compound (C1-3), 2.0 parts of the resin (D1) and 0.1 part of the catalyst (dodecylbenzenesulfonic acid) were mixed with dimethylacetamide. It melt | dissolved in the mixed solvent of 100 parts and 100 parts of methyl ethyl ketone, and prepared the coating liquid for 2nd intermediate | middle layers. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A 70 μm second intermediate layer was formed. The content of the electron transport material relative to the total mass of the electron transport material, the crosslinking agent, and the resin was 57% by mass.

(Examples 27 to 29)
The same as Example 26, except that the thickness of the second intermediate layer was changed from 0.70 μm to 0.35 μm (Example 27), 0.50 μm (Example 28), and 1.00 μm (Example 29). An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 26. The results are shown in Table 17.

(Examples 30 to 39)
The electron transport material of Example 26 was changed from (A101) to the electron transport material shown in Table 14, and the film thickness of the second intermediate layer was changed as shown in Table 14 in the same manner as in Example 26. An electrophotographic photoreceptor was produced and evaluated in the same manner. The results are shown in Table 17.

(Example 40)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  4.0 parts of electron transport material (A101), 5.8 parts of crosslinking agent [B1: protecting group (H1) = 5.1: 2.2 (mass ratio)], 0 of catalyst (dioctyltin laurate) .05 parts was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A 26 μm second intermediate layer was formed.

  The content of the electron transport material with respect to the total mass of the electron transport material, the crosslinking agent, and the resin was 41% by mass.

(Examples 41 to 43)
The thickness of the second intermediate layer was changed from 0.55 μm to 0.30 μm (Example 41), 0.70 μm (Example 42), and 1.02 μm (Example 43) as shown in Table 15. An electrophotographic photosensitive member was produced in the same manner as in Example 26, and the same evaluation as in Example 40 was performed. The results are shown in Table 17.

(Examples 44 to 64)
Except for changing the electron transport material as shown in Table 15 and changing the type of coating solution for the first intermediate layer, the thickness of the first intermediate layer, and the thickness of the second intermediate layer as shown in Table 15. An electrophotographic photoreceptor was produced in the same manner as in Example 40 and evaluated in the same manner. The results are shown in Table 17.

(Example 65)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  5.0 parts of the electron transport material (A101), 3.75 parts of the amine compound (C1-3), 0.1 parts of the catalyst (dodecylbenzenesulfonic acid), 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone. It melt | dissolved in the mixed solvent and prepared the coating liquid for 2nd intermediate | middle layers. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A 45 μm second intermediate layer was formed.

  The content of the electron transport material relative to the total mass of the electron transport material, the crosslinking agent, and the resin was 57% by mass.

(Examples 66 to 68)
The film thickness of the second intermediate layer was changed from 0.45 μm to 0.30 μm (Example 66), 0.72 μm (Example 67), and 1.10 μm (Example 68). An electrophotographic photosensitive member was manufactured and evaluated in the same manner as in Example 65. The results are shown in Table 17.

(Examples 69 to 89)
The electron transport material was changed to the electron transport material shown in Table 15, and the type of the first intermediate layer coating solution, the film thickness of the first intermediate layer, and the film thickness of the second intermediate layer were changed as shown in Table 15. Except for the above, an electrophotographic photosensitive member was produced in the same manner as in Example 65 and evaluated in the same manner. The results are shown in Table 17.

(Example 90)
An electrophotographic photosensitive member was produced in the same manner as in Example 41 except that the charge generation layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  10 of oxytitanium phthalocyanine (charge generating material) having peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° of the Bragg angle (2θ ± 0.2 °) in X-ray diffraction of CuKα. A department was prepared. 166 parts of this charge generation material and polyvinyl butyral resin (ESREC BX-1) were dissolved in a mixed solvent of cyclohexanone: water = 97: 3 to give a 5% by mass solution. Using this solution and 150 parts of a mixed solvent of cyclohexanone: water = 97: 3, together with 400 parts of 1 mmφ glass beads, the mixture was dispersed in a sand mill apparatus for 4 hours. Thereafter, 210 parts of a mixed solvent of cyclohexanone: water = 97: 3 and 260 parts of cyclohexanone were added to prepare a coating solution for a charge generation layer. The coating solution for charge generation layer was dip coated on the second intermediate layer to form a coating film, and the resulting coating film was dried at a temperature of 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm. .

(Example 91)
An electrophotographic photosensitive member was produced in the same manner as in Example 41 except that the charge generation layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  A charge generation layer coating solution is prepared by mixing and dispersing 20 parts of a bisazo pigment represented by the following structural formula (11) and 10 parts of a polyvinyl butyral resin (ESREC BX-1) together with 150 parts of tetrahydrofuran. did. And this coating liquid was dip-coated on the electron carrying layer, the coating film was formed, and the obtained coating film was dried for 30 minutes at the temperature of 110 degreeC, and the charge generation layer with a film thickness of 0.30 micrometer was formed.

(Example 92)
In the same manner as in Example 41 except that the benzidine compound represented by the above formula (9-2) in Example 1 was changed to a styryl compound (hole transport material) represented by the following formula (9-3). A body was prepared and evaluated in the same manner. The results are shown in Table 17.

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  2.4 parts of the electron transport material (A101), 4.2 parts of the isocyanate compound [B1: protecting group (H1) = 5.1: 2.2 (mass ratio)], 5.4 parts of the resin (D1), 0.05 parts of the catalyst (dioctyltin laurate) was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A 26 μm second intermediate layer was formed.

(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  3.2 parts of electron transport material (A101), 5 parts of isocyanate compound [B1: protecting group (H1) = 5.1: 2.2 (mass ratio)], 4.2 parts of resin (D1), catalyst 0.05 parts of (dioctyltin laurate) was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at 160 ° C. for 40 minutes to be cured, so that the film thickness is 0.26 μm. A second intermediate layer was formed.

(Comparative Examples 3 and 4)
An electrophotographic photosensitive member was produced and evaluated in the same manner as in Comparative Example 2 except that the thickness of the second intermediate layer was changed to 0.40 μm (Comparative Example 3) and 1.00 μm (Comparative Example 4). The results are shown in Table 17.

(Comparative Examples 5 to 8)
Example except that the film thickness of the second intermediate layer was changed to 1.25 μm (Comparative Example 5), 1.40 μm (Comparative Example 6), 1.50 μm (Comparative Example 7), and 2.00 μm (Comparative Example 8) In the same manner as in Example 1, an electrophotographic photoreceptor was produced and evaluated in the same manner. The results are shown in Table 17.

(Comparative Example 9)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  4 parts of electron transport material (A225), 3 parts of hexamethylene diisocyanate, and 4 parts of resin (D1) are dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone, and applied for the second intermediate layer. A liquid was prepared. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A second intermediate layer of 00 μm was formed.

(Comparative Example 10)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  5 parts of an electron transport material (A124), 2.5 parts of 2,4-toluene diisocyanate, and 2.5 parts of poly (p-hydroxystyrene) (trade name: Marcalinker, manufactured by Maruzen Petrochemical Co., Ltd.) It was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A 40 μm second intermediate layer was formed.

(Comparative Example 11)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  7 parts of the electron transport material (A124), 2 parts of 2,4-toluene diisocyanate, and 1 part of poly (p-hydroxystyrene) are dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone. A coating solution for two intermediate layers was prepared. The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at 160 ° C. for 40 minutes to be cured, whereby the film thickness is 0.40 μm. A second intermediate layer was formed.

(Comparative Example 12)
The surface-treated zinc oxide particles of the first intermediate layer coating solution 1 were changed to antimony-doped tin oxide fine particles (trade name: SN100D, manufactured by Ishihara Sangyo Co., Ltd.) to prepare a first intermediate layer coating solution. Using this first intermediate layer coating solution, a first intermediate layer having a film thickness of 6 μm was formed. Next, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the second intermediate layer was formed as follows and evaluated in the same manner. The results are shown in Table 17.

  A second intermediate layer was formed using a block copolymer represented by the following structural formula, a blocked isocyanate, and a vinyl chloride-vinyl acetate copolymer to form a second intermediate layer having a thickness of 0.32 μm.

(Comparative Example 13)
Using the coating solution 1 for the first intermediate layer, the same procedure as in Example 1 was performed, except that the first intermediate layer was formed so that the film thickness was 25 μm, and then the second intermediate layer was formed as follows. An electrophotographic photoreceptor was produced and evaluated in the same manner. The results are shown in Table 17.

  5 parts of alizarin (compound name: 1,2-dihydroxyanthraquinone, manufactured by Wako Pure Chemical Industries, Ltd.), 13.5 parts of cross-linking agent [B1: protecting group (H1) = 5.1: 2.2 (mass ratio)] 10 parts of resin (D1) and 0.05 part of dioctyltin laurate as a catalyst were dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare a coating solution for the second intermediate layer. . The coating solution for the second intermediate layer is dip-coated on the first intermediate layer to form a coating film, and the resulting coating film is heated at a temperature of 160 ° C. for 40 minutes to be cured. A second intermediate layer of 00 μm was formed.

Claims (15)

An electrophotographic photosensitive member having a laminate, a charge generation layer formed on the laminate, and a hole transport layer formed on the charge generation layer,
The laminate has a conductive support, a first intermediate layer formed on the conductive support, and a second intermediate layer formed on the first intermediate layer,
The first intermediate layer contains a binder resin and metal oxide particles surface-treated with an organic compound,
The second intermediate layer contains a cured product having electron transport properties,
The laminate has the following formula (1)
R_nV / R_0V ≦ 0.80 Formula (1)
(Where
For R_nV, a circular gold electrode having a thickness of 300 nm and a diameter of 12 mm is provided on the surface of the second intermediate layer by vapor deposition, and a DC electric field of −0.3 V / μm is applied from the conductive support to the gold electrode. It represents the impedance measured by applying an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz between the conductive support and the gold electrode while applying.
R_0V provides a circular gold electrode having a film thickness of 300 nm and a diameter of 12 mm on the surface of the second intermediate layer by vapor deposition, and applying a DC electric field of 0 V from the conductive support to the gold electrode, It represents impedance measured by applying an AC electric field of 3.0 × 10 ⁻³ V / μm and 0.1 Hz between the conductive support and the gold electrode. )
An electrophotographic photosensitive member characterized by satisfying the above. The laminate has the following formula (2)
0.40 ≦ R_nV / R_0V ≦ 0.75 Formula (2)
The electrophotographic photosensitive member according to claim 1, wherein:   The electrophotographic photoreceptor according to claim 1, wherein the organic compound is a compound having an alkoxysilyl group, an amino group, an epoxy group, a carboxyl group, a hydroxy group, or a thiol group.   The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the organic compound is a silane coupling agent. 5. The electrophotographic photosensitive member according to claim 1, wherein the first intermediate layer has a volume resistivity of 1.0 × 10 ⁸ Ω · cm or more. The electrophotographic photoreceptor according to claim 1, wherein the first intermediate layer has a volume resistivity of 1.0 × 10 ¹⁵ Ω · cm or less.   The electrophotographic photosensitive member according to claim 1, wherein the second intermediate layer has a thickness of 0.2 μm or more and 0.7 μm or less.   The cured product having an electron transporting property is a cured product of a composition containing an electron transporting material having a polymerizable functional group and a resin having a crosslinking agent and / or a polymerizable functional group. 2. The electrophotographic photosensitive member according to item 1.   The electrophotographic photosensitive member according to claim 8, wherein the content of the electron transport material having a polymerizable functional group is 30% by mass or more and 70% by mass or less with respect to the total mass of the composition.   The electrophotographic photoreceptor according to claim 8 or 9, wherein the crosslinking agent is at least one compound selected from the group consisting of an isocyanate compound, a melamine compound, and a guanamine compound. The resin having a polymerizable functional group is represented by the following formula (D)

(In the formula, R ⁶¹ represents a hydrogen atom or an alkyl group, Y ¹ represents a single bond, an alkylene group or a phenylene group, and W ¹ represents a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group. Is shown.)
The electrophotographic photosensitive member according to claim 8, which is a resin having a structural unit represented by:   The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer contains at least one charge generation material selected from the group consisting of a phthalocyanine pigment and an azo pigment.   The electrophotography according to any one of claims 1 to 12, wherein the hole transport layer contains at least one hole transport material selected from the group consisting of a triarylamine compound, a benzidine compound, and a styryl compound. Photoconductor.   An electrophotographic photosensitive member according to any one of claims 1 to 13, and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, are integrally supported, and A process cartridge that can be freely attached to and detached from the photographic device. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to any one of claims 1 to 13, a charging unit, an exposing unit, a developing unit, and a transferring unit.